Fastener



April-2, 1953 D. R. COLDREN r-:TAL 3,375,749

FASTENER Filed March 2, 1966 4 Sheets-Sheet 1 April 2, 1968 D. RcoLDRl-:N ETAL 3,375,749

FASTENER Filed March 2, 1966 4 Sheets-Sheet 2,

April 2, 1968 D. R. COLDREN ETAL 3,375,749

FASTENER Filed March 2, 1966 4 Sheets-Sheet 5.

April 2, 1968 D. R. COLDREN ETAL FASTENER 4 Sheets-Sheet 4 Filed March2, 1966 United States Patent O ABSTRACT OF THE DISCLOSURE A fastener isprovided for mechanically and electrically joining two members. Thefastener comprises a receptacle having resilient arms for cooperatingwith an insert. The insert permits a wide range of adjustability and isquickly connectable and disconnectable.

This application is a continuation-impart of our copending :applicationSer. No, 513,012 tiled Dec. 10, 1965.

This invention relates to the art of fasteners and more particularly toa new and novel means for electrically grounding `and mechanicallyfastening a printed circuit board to a chassis or the like, and to lanew and novel means for mechanically fastening any two members tgether.

It is an object of the present invention to provide a means for rapidlyconnecting a printed circuit board to a chassis.

A further object is to provide a means which will ground the printedcircuit board to the chassis.

A further object is to provide a fastening means which is of rigidconstruction and yet is relatively inexpensive to produce.

Another object is to provide a quick disconnect type fastening meanswhich securely holds two members together yet is releasable -by a slightrotational movement of the fastener. l v

Other objects and attainments of the present lnvention will become.apparent to those skilled in the art upon a reading of the followingdetailed vdescription when taken in conjunction with the drawings inwhich there are shown and described illustrative embodiments of theinvention; it is to be understood, however, that these emlbodi-rnentsare not intended to be exhaustive nor limiting of the invention but aregiven for purpose of illustration in order that others skilled in theart may fully understand the invention and the principles thereof andthe manner of applying it in practical use so that they may modify it invarious forms, each Ias may be best suited to the conditions of aparticular use.

In the drawings, in which like reference numerals refer to like parts:

FIGURE 1 is a perspective view of one embodiment of the presentinvention;

FIGURE 2 is a perspective view of an alternative form of the presentinvention;

FIGURE 3 is a perspective view of still another form of the invention;

FIGURE 4 is a cross-sectional view of a tab and fastener prior toengagement;

FIGURE 5 is a cross-sectional view of a tab and fastener in theirengaged position;

FIGURE 6 is a cross-sectional view showing a fastener mounted within aprinted circuit board;

FIGURE 7 is a cross-sectional view similar to FIG- URE 6 showing analternative configuration of the fastener;

FIGURES is a perspective view of an alternative form of the invention;

FIGURE 9 is a view showing a modified form of tab;

FIGURE 1-0i is a view partly in section of still another form of theinvention;

FIGURE 11 is a view looking in the direction of the arrows 11--11 inFIGURE 10;

FIGURE 12 is an exploded perspective view of a fastening insert andreceptacle constituting a further modification of the present invention;

FIGURE 13 is a side elevational view partly in section showing theinsert and receptacle of FIGURE 12 in their assembled form;

FIGURE 14 is a perspective view of a further modification of thefastener of FIGURE 12 for cooperation with a threaded member; and

FIGURE 15 is a side elevational view partly in section showing thereceptacle of FIGURE 14 in its mounted position ready to receive athreaded member.

With reference to FIGURE l there is show n a printed circuit board 10having a generally rectangular aperture 12 for receiving a fastenerindicated generally at 14. The fastener 14 has a strap portion 16 whichfits snugly within aperture 12 and is retained therein by means of twopair of flanges 18 and 20, the said flanges grasping opposite side wallsof the board 10. The anges 18 are electrically connected to suitableconductors on board 10 by means of dip soldering. Extending from strapportions 16 are a pair of arms 22 having inwardly turned ends 24. Thefastener 14 is preferably made out of steel but may be made of anymaterial which has sufficient resiliency to give spring characteristicsto the arms 22.

Fastener 14 is shown in FIGURE 4 about to receive a tab member 26 whichmay be struck from a suitable metallic chassis 28. The tab 26 isprovided with an indented portion 30 adjacent the end thereof. AIn-usewhen a chassis is to be secured to a printed circuit Iboard the tab 26is passed through the strap portion 16 of fastener 14 and between thearms 22 thereof. When the tab is fully seated Vthe indented portion 30ywill cooperate with the ends 24 of arms 22 to form a locking means tothereby prevent the subsequent separation of the -board member from thechassis. The tab can be seen in its seated position in FIGURE 5. It willhe noted that during insertion of ta-b 2 6 the end thereof will springthearms 22 outwardly prior to the seating of one of the arms into theindented portion 30. i

It can be seen at this point that fastener l14 and tab 26 provide ameans for mechanically connecting a printed circuit board to a chassis.It is also obvious that an electrical ground for the printed circuitboard has been provided, the electrical path being through Ithe fastener14 and tafb 26 into the metal chassis 28. Although fastener 14 has ybeenillustrated in conjunction with a printed circuit fboard and chassis itis to be understood that :this is a preferred use but not the only useof the fastener of the present invention. It is contemplated that thefastener and tab arrangement of the present invention may be used forinstalling door panels in automobiles, assembling ofce furniture,installing ceiling an-d wall panels, and assembling many other everydayproducts.

In FIGURE 2 there is shown a fastener 32 which is similar to fastener 14but variestherefrom in certain details to be described. The flanges 20of fastener 14 have 'been deleted in fastener 32 to thereby permit thefastener to be inserted through the aperture 12 in printed circuit hoard10 without the necessity of a subsequent forming operation. To retainthe fastener 32 in position there is provided a pair of lances 34 struckfrom the pair of arms 22, the said lances cooperating with the back sideof board 1Q, as seen in FIGURE 2, to thereby serve the same function asthe previously described flanges 2ll. As also seen in FIGURE 2 the ends2 4 of arms 22 have been provided with a serrated surface indicated at36. It has been found that the serrated surface at the ends of the arms22 provides Ebetter electrical characteristics than does the flatsurface as shown in FIGURE 1. It is obvious however that the fastener 14may also be provided with la serrated surface at the ends of the arms 22and likewise the fastener 32 may be provided with a flat surface inplace of the serrations in those instances of use where electricalcharacteristics are of little or no importance. In FIGURE 3 there isshown a fastener 38 which is identical to fastener 14 with the exceptionthat a pair of legs 40 extend from the arms 22 and overlie the oppositearm to which the leg is attached. These legs 40 limit the outwardmovement of the arms 22 and thereby prevent the overstressing of thearms.

In those applications where only a single fastener and tab are employedit may 'be often desirable to provide for the quick disconnect of theassembled parts. This may be achieved, with reference to FIGURE 7, byreplacing the rectangular strap portion 16 and aperture 12 withcorresponding parts having a generally square configuration. The tab 42is provided with indented portions 44 on opposite edges thereof forcooperation with the arms 22 of the fastener. When it is desired todisconnect the tab from the fastener all that is required is to rotatethe tab 90 degrees whereby the arms 22. `would be in engagement with thesmooth side edges of :the tab to thereby permit the easy withdrawal ofthe tab from the fastener. lf desired the corners of the tab 42 may berounded as indicated at 46 to facilitate the rotation of :the tab.

In FIGURE 8 there is shown a fastener 48 which is similar to thefastener 32 of FIGURE 2 with the exception that lance 50 is struck fromthe sides of the arms of the fastener rather than the center of thearms. The lance design of FIGURE 8 is advantageous in those situationswhere a very small fastener is used and a lance in the center of thearms would severely reduce the strength of the arms. Also by placing thelance at the sides of the arms the lances are more free lto moverelative to the arms with no problem of binding. The purpose of thelances 50 is the same as that of the lances 34 previously described.

The tab 26 described in connection with FIGURES 4 and 5 is integral withone of the parts to be connected i.e. the chassis 28. However thefastening concept of the present invention may be employed for joiningtwo members wherein the tab is a separate element. In FIGURE 9 there isshown a tab 52 which may fbe employed with any of the previouslydescribed fasteners. The tab 52 has an enlarged head 54 for Ilimitingthe insertion of the tab into the member to be connected. A plurality ofindents 56 and 58 are formed in opposite sides of the tab, the indentsS8 being offset from the indents 56. With this configuration the tab maybe inserted into a fastener such as 48 and the plural indents permit thetab to connect members of various thicknesses.

In FIGURES 10 and 11 there is shown a modified fastening arrangement.The arms 60, similar to the arms 22 previously described, are providedwith portions 62, adjacent their free ends, which extend at generallyright angles to the longitudinal extent of the fastener. The portions 62have semi-circular recesses 64 formed therein for receiving a threadedmember 66, the member 66 replacing the indented tabs of the previousembodiments.

Turning now to FIGURE 12 there is shown a fastening insert indicatedgenerally at 70 and a fastening receptacle indicated generally at 72which receptacle is adapted to receive the insert 70. The insert has anenlarged head 74 and an elongated section 76. The elongated section 76is of polygonal configuration and in the preferred embodiment shown isoctagonal. A series of equally spaced notches 78 are disposed inopposite sides of the insert and as can be seen in FIGURE 13 the notches78 are in transverse alignment. A second series of equally spacednotches 80 are disposed in opposite sides of the insert with the notchesbeing disposed in those sides which are 90 degrees removed from thesides containing the notches 78. The notches 80 are laterally offsetfrom the notches 78 :to provide a fine increment of adjustment as willbecome apparent as the description proceeds. Disposed between thenotched sides of the insert are plana-r faces 82 which provide adisconnect feature as will become apparent.

The receptacle 72 is formed from a flat sheet metal stamping into aboxlike configuration and comprises a rectangular strap portion 84having securing tines 86 extending from each side of said strap portion,the tines serving to secure the receptacle in position on a member to beconnected. A resilient spring finger 88 extends from each side of saidstrap portion on the opposite side from the securing tines 86, thefingers 88 having lances 90 formed therein, the lances terminating inapertures 92 serving as a strain relief to prevent cracking of therecepta-cle. The outer free ends 94 of the fingers 88 are bent inwardly`for cooperation with the notches on the insert 70.

As seen in FIGURE 13 the insert 70 and receptacle 72 are in theirassembled position. The receptacle is mounted within an aperture 96 in apanel 98 with the strap portion 84 being disposed within the apertureand the securing means 86 and lances 90 contacting opposite sides of thepanel 98 to thus retain the receptacle in position. The receptacle isinserted into the panel 98 from left to right as seen in FIGURE 13 withthe lances 90 being defiected inwardly during insertion and thenspringing outwardly into their securing position. A second panel 100 isshown with an aperture 102 through which extends the insert 70. The head74 of the insert limits the rightward movement of the insert into thepanel. The ends 94 of the fingers 88 will be cammed outwardly by theinsert and will eventually seat in either a pair of notches 78 or a pairof notches 80 depending on the thickness of the panels 98 and 100 whichare fastened together. As is evident two of the arms 88 will be inengagement with a pair of notches while the other two arms will merelyserve a steadying function. As shown in FIGURE 13 the forward finger 88,and the hidden rearward finger, are positioned in a pair of the notches80 while the upper and lower fingers have assumed an intermediateposition on the notches 7 8. The provision of offset notches allows foran increment of adjustment which is twice as fine as would be if thenotches 78 and 80 were in transverse alignment. The number of notches onany particular side of the insert is limited by the requirement of afairly gradual sloping surface on the notch to insure proper seating ofthe fingers 88.

The receptacle 104 shown in FIGURE 14 is similar to the receptacle 72previously described with the exception that the receptacle 104 has beenmodified to cooperate with a circular threaded member. The ends 106,108, and 112 of the spring fingers 114 are turned inwardly atapproximately 90 degrees to the longitudinal extent of the fingers 114so that the ends will engage deeply with the threads of a mating member.The extreme ends of the fingers are provided with bevelled surfaces suchas 116 which surfaces approximate the configuration of a standardthread. Further the -spring fingers are provided with arcuate recesses118 in ends thereof which recesses approximate the circumference of athreaded member.

As best seen in FIGURE 15 the ends 106 through 112 of the spring fingers114 are disposed at a slight angle relative to a transverse planepassing through the receptacle, this angle being approximately 5degrees, the angle chosen being dependent on the lead of the particularthread design on a mating part such as 120. The spring arms having ends106 and 110 are slightly longer than the spring arms having ends 108 and112. Because of this configuration the ends 106 and 108 will engage onethread on the member 120 while the ends 110 and 112 will engage theadjacent thread. The provision of two long and two short spring armsallows all of the arms to be of approximately the same length. If thearms were designed to be of gradually increasing or gradually decreasinglength whereby all four arms would engage the same thread there would bea wide variation in length between the longest and the sho-rtest arm,which arrangement would adversely affect the stability of the receptacleand would require that the receptacle be longer than is actuallynecessary.

It can thus be seen that a fastener has been provided which achieves theobjectives of the invention. The fastener is extremely versatile in thatit has possible use in many applications requiring the joining togetherof two members.

Changes in construction will occur to those skilled in the art andvarious apparently different modifications and embodiments may be madewithout departing from the scope of the invention. The matter set forthin the foregoing description and accompanying drawings is offered by wayof illustration only. The actual scope of the invention is intended tobe defined in the following claims when viewed in their properperspective against the prior art.

What is claimed is:

1. A fastening device for connecting a first member to a second membercomprising in combination a receptacle having a generally rectangularstrap portion, said strap portion being adapted to seat within anaperture in said first member, means extending from said strap portionfor securing said receptacle to said rst member, a resilient armextending from each side of said strap portion and having one end fixedthereto, said arms having their free ends converging towards each other,an insert adapted to extend through an aperture in lsaid second memberand having an enlarged end to prevent passage of said insert completelythrough said second member, said insert comprising an elongated elementof generally polygonal configuration, a first and second plurality ofnotches disposed in a first and second side respectively of said member,said first and second sides being oppositely disposed, said first andsecond plurality of notches being in transverse alignment, and a thirdand fourth plurality of notches disposed in a third and fourth siderespectively of said member, said third and fourth sides beingoppositely disposed and approximately 9() degrees from said first andsecond sides, said third and fourth plurality of notches being intransverse alignment and being longitudinally offset from said first andsecond plurality of notches, whereby the free ends of a pair of oppositeones of said arms will engage a pair of opposite ones of said notchesupon insertion of said insert into said receptacle to thereby securesaid first member to said second member.

2. A fastening insert comprising an elongated member of generallypolygonal configuration, a first and second plurality of notchesdisposed in a first and second side respectively of said member, saidfirst and second sides being oppositely disposed, said first and secondplurality of notches being in transverse alignment and a third andfourth plurality of notches disposed in a third and fourth siderespectively of said member, said third and fourth `sides beingoppositely disposed and approximately degrees from said first and secondsides, said third and fourth plurality of notches being in transversealignment and being longitudinally offset from said first and secondplurality of notches.

3. A fastening insert as set forth in claim 2 further comprising twopairs of oppositely disposed longitudinally extending planar faces, eachsaid face lying vbetween adjacent sides of said member whereby saidmember has a generally octagonal cross-sectional configuration.

4. A fastening receptacle comprising a generally rectangular strapportion, a resilient arm extending from each side of said strap portionand having one end fixed thereto, said arms having their free endsconverging towards each other and disposed at approximately 90 degreesto the longitudinal extent of said receptacle, each said free end havingan arcuate recess formed therein and being obliquely disposed relativeto said receptacle, flange means extending from said strap portion, andlance means formed in each of said arms, said lance means cooperatingwith said flange means for retaining said receptacle on a mountingmember.

References Cited UNITED STATES PATENTS 2,552,066 5/1951 Sorensen 85--5 X2,741,938 4/1956 Johnson 85-8.8 2,906,159 9/1959 Meyer 85-36 2,936,6685/1960 Meyer 85 80 X 3,182,367 5/1965 Hamann et al. 24-73 3,226,14512/1965 Goldberg 85-80 X ROY D. FRAZIER, Primary Examiner. I. F. FOSS,Assistant Examiner.

